I lost a decade of family photos using a Western Digital RAID-in-a-box setup (WD MyCloud or something)
Both hard disks fried at the same time.
Both hard disks fried at the same time.
I'm sorry for your family pictures: it's the one personal thing I've got copies of everywhere (online / offline / on-site / off-site).
But... Regarding HDDs/SSDs failing at the same time: the common mantra is to be very careful of disks from the same batch. There have been SSDs too failing after a certain amount of hours of usage.
I like to use different brands or, at the very least, different models from the same brand.
Now I'm not saying it's what happened in our case: if they literally fried, then it's another problem.
1) I never sit and look at old photos. I've barely got enough time in the day to take care of the present.
2) I don't want to worry about organizing, preserving, and/or losing them.
I have a few family portraits from over the years that are framed and hang on the wall. That's enough.
Is it possible to mix disks from different manufacturers in a RAID?
But a way around what you mention, keeping it to a single manufacturer: is to buy the drives from different retailers, hopefully geographically dispersed, a few weeks apart, to ensure you get drives from different manufacturing batches.
Unless there's a systemic issue with the entire product line (unlikely to go unnoticed) you spread out the risk of a single bad batch that way.
Maybe overkill, but that's what I did many years ago.
I'm not sure to the extent hardware RAID cares these days. NAS boxes from hard drive manufacturers might care about the drive vendor, but I've never used them.